Which imaging feature is typical of an epidural hematoma?

Which imaging feature is typical of an epidural hematoma?

• A. Crescent-shaped and can cross sutures
• B. Biconvex lens-shaped and does not cross sutures
• C. Diffuse brain swelling without a discrete collection
• D. Ring-shaped around the ventricles

Answer: (B)

Epidural hematoma on CT classically appears as a biconvex (lens-shaped) collection that does not cross suture lines. This shape arises because the bleeding sits between the skull and the dura, typically from an arterial injury such as the middle meningeal artery after a head fracture, and the sutures of the skull prevent the hematoma from spreading across the skull. This pattern helps distinguish it from other bleed types, like subdural hematoma, which is crescent-shaped and can cross sutures. If not recognized and treated, the epidural collection can rapidly enlarge and increase pressure, risking brain herniation.

Epidural hematoma on CT classically appears as a biconvex (lens-shaped) collection that does not cross suture lines. This shape arises because the bleeding sits between the skull and the dura, typically from an arterial injury such as the middle meningeal artery after a head fracture, and the sutures of the skull prevent the hematoma from spreading across the skull. This pattern helps distinguish it from other bleed types, like subdural hematoma, which is crescent-shaped and can cross sutures. If not recognized and treated, the epidural collection can rapidly enlarge and increase pressure, risking brain herniation.